%&LaTeX
\documentclass{article}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{textcomp}

\begin{document}

\begin{thebibliography}{5}

\bibitem{Mueller_etal2014} M{\"u}ller, C., Elliott, J., \& Levermann, A. (2014). Food security: Fertilizing hidden hunger. \textit{Nat. Clim. Change}, \textit{4}(7), 540--541.

\end{thebibliography}

\end{document}

